Pre-heat oven to 350°F.
Place meatloaf muffins in the oven and bake for 25-35 minutes until they reach 155°F.
While meatloaf is baking, heat oil in a sauté pan over medium-high heat.
Add the onions, season with salt and pepper. Cook for about 10 minutes until brown and caramelized.
In another pan, heat milk on medium heat.
Combine cornstarch and water in a bowl to make a slurry.
Add to milk and cook until thickens.
Add the shredded cheese and melt to incorporate the cheese. (It may look split.)
Place in a blender and blend on high to combine.
Season with cayenne, Tabasco, salt and pepper.
Remove meatloaf from the oven, slice and place onto submarine buns.
Top with caramelized onions and smother with cheese sauce.